Fair Value (Instruments Not Measured at Fair Value) (Details) - USD ($) $ in Millions		Jun. 30, 2021	Dec. 31, 2020
Carrying Amount [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	$ 108	$ 97
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		16,535	16,354
Recourse debt		3,375	3,446
Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Value added tax		3	4
Accounts receivable - noncurrent	[1]	199	197
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		17,646	18,403
Recourse debt		3,525	3,677
Level 1 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent		0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		0	5
Recourse debt		0	0
Level 2 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent		0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		17,619	15,301
Recourse debt		3,525	3,677
Level 3 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	199	197
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		27	3,097
Recourse debt		$ 0	$ 0

[1] These amounts primarily relate to amounts due from CAMMESA, the administrator of the wholesale electricity market in Argentina, and amounts impacted by the Stabilization Fund enacted by the Chilean government, and are included in Other noncurrent assets in the accompanying Condensed Consolidated Balance Sheets. The fair value and carrying amount of these receivables exclude VAT of $3 million and $4 million as of June 30, 2021 and December 31, 2020, respectively.